Pure Humidifier EC Series User manual

1
Standard Water
“EC” Series
Electric Humidifier
Installation Instructions
—————————————————
Operation and Maintenance Manual
Form No: ECOM-10-19
READ AND SAVE THESE INSTRUCTIONS
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PURE HUMIDIFIER® and INTAC® are registered trademarks of PURE Humidifier Co.

1
Introduction
To the user of PURE Humidifier Co.’s
Electric Humidifiers
We at PURE Humidifier Co. thank you for choosing
one of our quality products. PURE Humidifier Co.
Electric Series Humidifiers are models of simplicity
to install, operate, and maintain. However, they
must be maintained to provide maximum operating
efficiency.
PLEASE READ AND FOLLOW ALL
INSTRUCTIONS CAREFULLY. PROPER
OPERATION AND HUMIDITY CONTROL IS
POSSIBLE ONLY WITH PROPER INSTALLATION
AND MAINTENANCE.
The “EC” Series Humidifier utilizes a Tri-Probe
Sensor conductive-type water control system, which
is designed for use with standard (hard or soft) tap
water. Use of deionized, demineralized, or reverse
osmosis water will cause a failure of the water level
control system and void the warranty.
High chloride content in feed water can cause
chloride stress cracking and chloride pitting in
stainless components. Chloride stress corrosion
cracking (CSCC) and chloride pitting of stainless
steel components is not covered by warranty. Do
not use hydrochloric acid descalers or bleach to
clean the tank. We offer an easy-to-use, non-toxic
descaling solution to help keep your units clean and
operating with maximum efficiency. Please contact
your local PURE Humidifier representative for more
information about our PURE Clean descaling
solution.
PURE Humidifier Co.’s “ECDDR” Series should be
installed on applications that require deionized,
demineralized, or reverse osmosis water.
To ensure proper installation of this product, it must
be installed by qualified HVAC and electrical
contractors, and must be in compliance with local,
state, federal, and governing codes. If installed
improperly this product may cause damage to
property, severe personal injury, or death as a result
of electric shock, burns, and/or fire.
Do not adjust any components inside humidifier
control panel without consulting the factory.
Installation of humidifier in high humidity or salt
water atmospheres will cause accelerated corrosion,
resulting in a reduction of the normal lifespan of the
unit.
For indoor use only.
Table of Contents
Introduction 1
Capacity & Electrical Specifications 2
Dimensions & Layout 3
Humidifier Layout 4
Location & Mounting 5
Wall Mounting Detail 6
Dispersion Methods 7
Injection Tube and Flexible Hose 8
Steam Supply Piping Examples 9
Piping 10
Blower Pack 11-12
Pre-Startup Checklist 13
Non-INTAC® Startup Procedure 14
INTAC® Startup Procedure 15
Maintenance & Cleaning Instructions 16
Cover Gasket Replacement Instructions 17
Troubleshooting 18
Tool Requirements & Torque List 19
Maintenance Notes 20
Exploded Parts Drawing 21
Parts List 22
The PURE Humidifier Co. Warranty
PURE Humidifier Co. guarantees its products to be free from
defects in material and workmanship for a period of one year
from the date of shipment; provided the product is properly
installed, serviced, and put into the service for which it was
intended.
PURE Humidifier Co. is obligated under the terms of this
warranty to the repair or replacement of the defective part(s),
excluding any labor charges, or to refund the purchase price at
our option. PURE Humidifier Co. assumes no obligation for
incidental or consequential damages. The above provisions
are in lieu of all other guarantees, obligations, liabilities or
warranties, expressed or implied.

2
Capacity & Weights
Electrical Specifications
Electrical Specification
“EC” Series
Standard
Water Unit
Model No.
Steam Output Capacity † Humidifier Weight
Empty Full
lbs/hr kg/hr lbs kg lbs kg
EC-5 15.0 6.8 139.0 63.1 223.0 101.2
EC-10 30.0 13.6 140.0 63.5 224.0 101.6
EC-15 45.0 20.4 141.0 64.0 225.0 102.1
EC-20 60.0 27.2 142.0 64.4 226.0 102.5
EC-25 75.0 34.0 143.0 64.9 227.0 103.0
EC-35 102.0 46.3 146.0 66.2 230.0 104.3
Capacity & Weights
“EC” Series
Standard
Water Unit
Model No.
Single Phase Amperage
Control
Circuit
Voltage
KW No. of Heaters 120V 208V 240V 480V 600V No. of Heaters 208V 240V 480V 600V
EC-5 5 Single 41.7* 24.0 20.8 10.4 8.3 Triple 13.9 12.0 6.0 4.8 24 vac
EC-10 10 Double 41.7 20.8 16.7 Triple 27.8 24.1 12.0 9.6 24 vac
EC-15 15 Triple 31.3 25.0 Triple 41.7 36.1 18.1 14.4 24 vac
EC-20 20 Triple 41.7 33.3 Triple 24.1 19.2 24 vac
EC-25 25 Triple 41.7 Triple 30.1 24.1 24 vac
Three Phase Amperage
EC-35 34 Triple Triple 40.9 32.7 24 vac
* EC-5 at 120/1 requires 3 heating elements.
† The above capacities are based on 100% efficiency. Actual humidifier capacity may vary due to the heat loss
from the humidifier reservoir. The ambient air temperature, air velocity, and injection tube system will affect
the rate of heat loss from the humidifier reservoir.

3
Dimensions & Layout
14.75”
(37.5)
17.00”
(43.2)
7.75”
(19.7)
29.50”
(74.9)
Removable
Access Plate*
2 3/8” Steam
Outlet Access
TOP VIEW
24”
(60.9)
Removable Key Locked
Reservoir Access Door Operation Status
Indicating Lights
FRONT VIEW RIGHT SIDE
VIEW
BOTTOM VIEW
Key Locked
Electrical
Access Door
Reservoir Drain Outlet
1 7/8”Ø 2.375”
(6.0)
8.4375”
(21.4)
15.00”
(38.1)
2.00”
(5.1)
1.50”
(3.8)
Cabinet Overflow
1/2” NPT
Water Inlet 3/8” NPT
Electrical Inlet 1 1/8ӯ
NOTE: Dimensions are typical for all EC models.
6.50”
(16.5)
16”
(40.6) Key Locked Electrical
Access Door **
*Removable access plate allows reservoir to
slide out for inspection and cleaning without
disconnecting the steam supply piping.
**See local codes for minimum clearance to
electrical compartment. The electrical access
door requires a minimum clearance of 16" to
fully open.

4
Humidifier Features
 SCR modulating control
 Visible status and diagnostic LED indicator lights
 Electronic water level control system
 Accumulative automatic timed drain system
 Seasonal end-of-use drain system*
 High efficiency incoloy immersion water heaters
 18 gauge steel cabinet with baked enamel paint
finish
 Internal stainless steel evaporating reservoir
mounted on slides for easy removal
* Optional features
 Key locked doors for both reservoir and electrical
access
 Easy and simple installation options
 Dispersion methods include Insty-Pac*, Fast-Pac*
Injection Tube*, or Blower Pack assembly* for
room distribution
 Manual reset over-temperature safety switch
 INTAC®microprocessor control system*
 VAV dual modulating control system*
Removable Key Locked
Reservoir Access Door
Humidifier Layout
Steam Outlet
Connection
Over-Temperature
Switch
Removable
Humidifier
Cover
Removable
Humidifier
Reservoir
Immersion
Heaters
Tri-Probe
Sensor
1/4"-IPS Water
Inlet and Strainer
Operating Status
Indicating Lights

5
Location
The location selected must provide for electrical service,
cold or hot water supply, and sanitary drain.
When selecting a location, try to keep the humidifier
within 10 feet (305 cm) of the duct to avoid unnecessary
heat losses, condensation within the steam supply line
and excessive pressure buildup in the reservoir.
Visible “fog” will saturate and condense when it contacts
objects such as turning vanes, filters, fans, elbows, or
take-offs. The warmer the air, the more easily it will
dissipate the visible steam. The most active and
warmest portion of the duct will provide better mixing of
the steam and air. The injection tube should be
mounted a minimum of 2 feet (61 cm) downstream from
an elbow or other uneven air flow area.
Avoid mounting single-style injection tube(s) closer than
8-10 feet (244-305 cm) upstream of objects that could
become saturated and condense the steam (reference
paragraph above). If the duct layout does not provide a
straight, unobstructed run of 8-10 feet (244-305 cm), a
multiple injection tube system should be considered to
reduce the visible steam travel distance.
For Fast-Pac and Insty-Pac multiple tube assemblies
please consult factory for job specific non-wetting
distances.
Reference Fast-Pac or Insty-Pac O&M’s for full
installation details.
CAUTION: Do not humidify upstream of filters. Consult
factory.
CAUTION: Smoke detectors should not be located
downstream of injection tube assemblies.
Location of Control Sensors
It is important to avoid mounting any control sensors
within the visible steam. The control sensors should be
mounted a minimum of 8-10 feet (244-305 cm)
downstream from the humidifier injection tube. Due to
the temperature rise that exists within the visible steam
dissipation area, thermostats should not be mounted
near the injection tube.
High-limit humidistats should be installed before any
duct obstruction to make sure the humidifier is
interrupted before saturation can occur on the object.
The high-limit should be mounted a minimum of 8-10
feet (244-305 cm) downstream from the injection tube.
Installing the high-limit closer than 8 feet (244 cm) from
the humidifier may cause erratic control.
Mounting
Mounted on the wall. The humidifier should be mounted
dead level in both directions. PURE Humidifier Co.
supplies the wall mounting bracket. Bracket is mounted
to wall studs first. The bracket must be mounted to wall
studs or additional support must be provided in the field.
EC cabinet is then hung on the slip-fit bracket.
Drain Pan Mounting
A drain pan is an additional safety feature which may be
required to be supplied in the field. In a proper
humidifier installation, a drain pan is not required.
However, if the humidifier and injection tube are located
in an area that contains valuable equipment or is a
water sensitive area, PURE Humidifier Co. recommends
the addition of a drain pan under the injection tube. The
drain pan should extend a minimum of 3 feet (91 cm)
downstream from the injection tube. The pan should be
of a size which is sufficient to retain sudden drainage of
the humidifier’s contents. The pan should be drained to
a sanitary drain.
Injection Tube Installation
Single tube units should have the injection tube installed
in the center of the duct. Multiple tube units should have
the tubes staggered within the duct. See Injection Tube
and Flexible Hose Installation on page 8 for details.
Injection tube should be pitched 2 inches (5 cm) per foot
(31 cm), back to the humidifier. If proper pitch cannot
be maintained, or the injection tube is mounted lower
than the humidifier, a drain “tee” will be required.
Install the tube with the steam ports injecting steam up.
NOTE: If narrow ducts (6”/15 cm or less, in height) are
utilized, install the tube with the steam ports injecting
with the air flow slightly (2 o’clock position).
Galvanized steel duct plates are provided to seal the
opening where the tube enters the duct.
Multiple Injection Tube Assemblies
See page 9 for details.
Location & Mounting

6
Wall Mounting Detail
Mounting
The humidifier should be mounted dead level in both directions. PURE
Humidifier Co. supplies a wall mounting bracket. Bracket is mounted to wall
studs first. The bracket must be mounted to wall studs or additional support
must be provided in the field. EC cabinet is then hung on slip-fit bracket.

7
Dispersion Methods
Injection Tube and Flexible Hose
Allows remote mounting of the humidifier
reservoir from the duct. Also allows the
humidifier to be located below a wall-
mounted duct. See page 8 for details.
Insty-Pac and Fast-Pac
Multiple Injection Tube Assemblies
For applications where you need a short
dissipation distance. Allows remote
mounting of the humidifier reservoir from
the duct. Also allows the humidifier to be
located below a wall-mounted duct. See
page 9 for details.
Blower Pack for Direct Room Humidification
Allows humidifier to be mounted directly on
the wall within the space to be humidified.
See page 11 and 12 for details.

8
Installation
Injection tube shall be installed in the center
of the duct. Hose and injection tube should
be pitched back to the humidifier two inches
(5 cm) per foot (31 cm). If proper pitch cannot
be maintained, or the injection tube is
mounted lower than the humidifier, a drain
"tee" will be required (reference drain "tee"
illustration).
Install the tube with the steam ports injecting
steam up. NOTE: If narrow ducts (6”/15 cm
or less, in height) are utilized, install the tube
with the steam ports injecting slightly with the
air flow (2 o’clock position).
The hose connects to the injection tube and
humidifier with stainless steel hose clamps
(by PURE Humidifier Co.).
Galvanized steel duct plates are provided to
seal the opening where the tube enters the
duct.
“H”
Water
Seal
Height
Total KW
5 thru 20
21 thru 34
“H”
6” (15 cm)
8” (20 cm)
Typical “EC” Series
Electric Humidifier
3/4” SW Condensate
drain line (by others)
∆The water seal height may have to
be increased if excessive duct
static pressure exists.
Open Sanitary
Drain
Water Seal Height ∆
Flexible Hose
Stainless Steel
Drain Tee
(optional) Duct (beneath
humidifier)
Flexible Hose
Pitch 2” (5 cm) per foot (31 cm)
back to the humidifier.
Duct Plate
Injection Tube
Pitch 2” (5 cm) per foot (31 cm)
back towards the humidifier.
Duct
Typical “EC” Series Electric
Humidifier
Injection Tube and Flexible Hose
4” Insertion Length/
Duct Width
8”
Tube Detail
1 1/2ӯ

9
Steam Supply Piping Examples
Pitched Towards Steam Generator
Pitched Towards Steam Generator
and Tube Assembly
1/4”/1’
2”/1’
Pitch
(see NOTE 1)
2”/1’
Notes:
1. Pitch hard piping or flexible hose 2" per foot if steam is flowing uphill, 1/4" per foot if the steam is flowing
downhill. Reference piping examples shown.
2. When feasible to do so, install a minimum one-foot riser from the top of the tank to reduce condensate carryover.
3. Use flex connectors or unions to allow for easy removal of cover.
4. Support flexible hose every 18" to avoid sagging.
5. Hard piping or flexible hose must match reservoir outlet size. Do not use supply piping with a smaller inside diameter
than the reservoir outlet.
6. Failure to follow the piping recommendation on this page may result in blown water seals, leaking cover gasket, or
dispersion tubes spitting.
7. Install a Drain Tee at any low spots in supply piping run where condensate will accumulate. All horizontal to vertical
up transitions require a water-sealed drip leg.
8. Reference job specific tube assembly O&M included with your order for complete details.
Pitched Towards Tube Assembly
Pitched Towards Drain Tee
Drain Tee
(see NOTE 7)
1/4”/1’ 2”/1’
1/4”/1’
Use two 45° elbows for
hard piping or wide 90° for
flexible steam hose
Supply piping
connectors
(see NOTE 4)
see NOTE
Typical
Humidifier
Reservoir
see NOTE
see NOTE
see NOTE

10
Drain Piping
The “EC” style humidifier requires two copper drain
piping connections run to an open drain.
The drain piping should be copper or stainless steel.
The use of PVC piping is not recommended; the
humidifier water temperature may cause the PVC to
soften and fail. Use a drain tempering kit before
transition to PVC.
The “EC” humidifier has a factory-piped internal
water seal/overflow. The water seal must be filled
(primed) prior to operation. Remove the Tri-Probe
sensor from the tank until the water overflows into
and primes the water seal. Once this is done
replace the Tri-Probe sensor.
If gravity drain is not possible please use a
condensate pump rated for 212°F water or contact a
PURE Humidifier Co. representative to purchase
one.
Typical “EC” Series
Humidifier (Right
Side View)
3/4” Drain
Open Sanitary
Drain
3/8” NPT Water Inlet
WARNING:
Humidifier Reservoir Drain and Cabinet
Overflow Drain (see page 3) MUST be run
separately. These lines CANNOT be tied
together into a common drain line. Draining
malfunction will occur causing damage to the
humidifier system.
Piping
Cabinet Overflow
Drain
Water Supply Piping
This style humidifier utilizes a Tri-Probe Sensor
conductive-type water control system that is
designed for use with standard (hard or softened)
tap water. Use of deionized, demineralized, or
reverse osmosis water will cause failure of the
water level control system and void the humidifier
warranty.
Cold or hot standard tap water can be supplied to
the humidifier. A minimum water pressure of 35 psi
(2.4 Bar) should be maintained to provide the
proper water level within the humidifier. DO NOT
exceed the maximum acceptable water pressure of
60 psi (4.1 Bar). If the water pressure is above 60
psi (4.1 Bar) a pressure reducing valve should be
installed. Failure to do so will cause the supply
water hose to burst due to excessive heat and
pressure.
The humidifier has a factory built-in 1.5” (4 cm) air
gap between the water inlet and the overflow.
Local codes should be checked to see if the
addition of a vacuum braking device is required.
Water connection is made at the bottom of the
humidifier with 3/8” NPT piping.

11
Optional Blower Pack
In applications where a ducted air system is not
available, PURE offers the optional Blower Pack.
The Blower Pack contains a two-speed
adjustable blower that moves the air over the
steam discharge outlet and disperses the steam
directly into the space (see Fig. 1). The Blower
Pack mounts directly on top of the “EC”
humidifier or can be remote mounted (see Fig.
2).
Locating Blower Pack
The distance that visible steam will travel after
leaving the Blower Pack is dependent upon the
relative humidity in the room and the capacity of
the humidifier. If this visible steam comes in
contact with any solid object (walls, beams,
machinery, etc.), it may form condensate and
drip. Refer to Fig. 3 and Table 4 (Table 4 is
located on page 12) for data on visible steam
travel. This will aid you in planning the location
of the Blower Pack.
Remote Mounting
The Blower Pack may be remote-mounted up to
ten feet away from the “EC” wall mount
humidifier (see Fig. 2).
Blower Pack Air is drawn
into Blower Pack
Steam is discharged
directly into space
“EC” Wall Mount Humidifier
“EC” With Optional Blower Pack
Fig. 1
Visible Rise and Throw
Fig. 3 Remote-Mounted Blower Pack Fig. 2
Throw
Rise
Blower Pack
Remote Blower Pack
“EC” Humidifier
6” Water Seal

12
Locating Blower Pack
The distance that visible steam will travel after leaving the Blower Pack is dependent upon the relative
humidity in the room and the capacity of the humidifier. If this visible steam comes in contact with any
solid object (walls, beams, machinery, etc.) it may form condensate and drip. Refer to Fig. 3 (Fig. 3 is
located on page 11) and Table 4 for data on visible steam travel. This will aid you in planning the loca-
tion of the Blower Pack.
Visible Steam
Rise & Throw Humidifier Model
EC-5 EC-10 EC-15 EC-20 EC-25 EC-35
50%
RH
Rise (ft) 1’ 2’ 3’ 4’ 5.5’ 8’
Throw (ft) 8’ 10’ 13’ 16’ 18’ 23’
Rise (ft) 2’ 3’ 4’ 5’ 6’ 8’
Throw (ft) 13’ 14’ 16’ 18’ 20’ 25’
60%
RH
Throw is the horizontal distance the visible steam travels from the steam discharge.
Rise is the vertical distance the visible steam travels from the steam discharge.
Objects in the direct line of the visible steam or objects that are cooler than the ambient temperature may
accumulate condensation.
NOTE: Data above based on 70°F room temperature.
Table 4
Optional Blower Pack Dimensions
Fig. 5
Blower Pack weight is 60 lbs (27.2 kg)
* Blower requires a separate 120/1 circuit (by others)
Blower Pack
296/435 CFM Fan
120/1/60*, 2.17 amps
1/15 HP
17”
(43.18)
7.75”
(19.6)
Left Side View Front View
15”
(38.1)
29.50”
(74.93)
14.75”
(37.47)
1/4” NPT Drain Connection
Steam
Discharge
Steam Inlet

13
Pre-Startup Checklist
Pre-Startup Checklist
Before starting the “EC” PURE Humidifier Co. Electric Humidifier, check the following installation items:
______ 1. MOUNTING - Verify that the humidifier evaporating chamber is securely supported and that the
evaporating chamber is level in both directions.
______ 2. INJECTION TUBE - Verify that the humidifier injection tube is mounted within the duct with the proper
pitch back to the humidifier (2”/5 cm per foot / 31 cm). NOTE: If the humidifier evaporating chamber or
the flexible hose (optional) is mounted higher than the injection tube, a drain “tee” is required to drain the
condensate out of the injection tube steam line. If it is an Insty-Pac or Fast-Pac, refer to the respective
O&M to determine if they are mounted properly and have the proper p-trap size.
______ 3. ELECTRICAL - Verify that all wiring connections have been connected in accordance with the wiring
diagram. CAUTION: Live power may exist in the control cabinet. Turn off the main power at the
disconnect switch before verifying the electrical connections!
______ 4. SAFETY CONTROLS – The supply air duct RH high-limit should be installed at least 10 feet
downstream from the humidifier tube(s). Any other control sensors should be at least 10 feet
downstream from the humidifier tube(s). Smoke detectors should not be installed downstream of the
humidifier tube(s). If a smoke detector absolutely has to be installed downstream from the humidifier
tubes then it should be installed as far from the tubes as possible.
_____ 5. PIPING: Water Supply - Verify that all piping connections have been completed as recommended and
that water pressure is available to the humidifier. Verify that the supply water pressure is 35-60 psi.
There should be at least 5 feet of metal pipe and check valve between the tank and any plastic pipe.
_____ 6. PIPING: Steam Outlet - Refer to attachment for proper outlet steam piping from the generator to the
tube(s). Any horizontal to vertical up transition in the outlet steam pipe requires a water-sealed
drip leg! Improper outlet steam piping will cause steam to leak from the steam generator. Runs over
20 feet long may require upsizing of the steam pipe.
Signature:__________________________ Date:_________

14
Non-INTAC®Startup Procedure
Start Up Procedure
______ 1. With the power "off", set the switch on the control board to the "Standby" position (the control board is
located within the humidifier control panel door).
______ 2. Make sure the manual drain valve lever (located on the front of the drain valve) is in the “closed”
position.
______ 3. Turn the controlling humidistat to the lowest setting (no call for humidity).
______ 4. Turn the electric power “on” to the humidifier. The “Power” LED light on the controller should be
illuminated.
______ 5. Set the switch on the control board to the "Normal" position.
______ 6. Open the water supply on/off control valve (by others) and allow the humidifier evaporating chamber to
fill to the proper level.
______ 7. After the humidifier is full of water, the "Water Level Full" LED will illuminate. Turn the humidistat up to
call for humidifier demand.
______ 8. Make sure all the optional safety switches are satisfied (airflow proving switch, high-limit humidistat,
etc.).
______ 9. The heater(s) should energize on a call from the humidistat.
______ 10. Verify the low water safety circuit by closing the water supply and opening the manual drain lever on
the drain valve. As the humidifier tank is draining, the "Water Level Full" and "Heater Energized"
lights should go out and you should hear the contactor drop out when the low water level is reached;
this indicates the low water safety circuit is operational. This should only take a couple of minutes
maximum.
______ 11. Close the drain valve and allow the humidifier to fill to the proper level.
______ 12. Check operation of optional field-installed safety switches (airflow proving switch, high-limit humidistat,
etc.) to make sure that they turn the power off to the control circuit power. The safety switches should
shut-off the humidifier heaters whenever one or more of the optional safety switches create an “open
circuit”.
______ 13. Check heater amperage draw by testing and recording voltage and amperage in each phase.
Readings should match the factory heater nameplate.
Amps A:_______ Amps B:______ Amps C:______
______ 14. Inspect installation for leaks by operating humidifier at a full rolling boil. This may take up to 15 minutes
from a cold start. Any leaks should be sealed. Just tightening a pressure clamp will not work if the
gasket is not properly positioned between the sealing surfaces. If necessary, remove the cover, reseat
gasket and replace the cover. A small amount of adhesive (super glue, gorilla glue, spray adhesive,
etc.) to hold the gasket in place while repositioning the cover will aid in this process.
______ 15. After the unit is producing steam, check and retighten all hose clamp connections in the system and
make sure they are torqued to 35-40 in-lbs. There are 6 clamps total inside the cabinet.
Signature:__________________________ Date:_________

15
INTAC®Startup Procedure
Start Up Procedure
______ 1. Make sure the manual drain valve lever (located on the front of the drain valve) is in the “closed”
position.
______ 2. Turn the electric power “on” to the humidifier. The LCD display on the INTAC®controller should
illuminate “H2O Level Low - E07”. The “System Fault” LED should be illuminated
______ 3. Set menu 101 “RH Setpoint” to the lowest setting (no call for humidity). If 100 menu shows “No
Parameters Available” the procedure must be done through the Building Management System.
Consult the INTAC®manual for further instructions.
______ 4. Open the water supply on/off control valve (by others) and allow the humidifier evaporating
chamber to fill to the proper level.
______ 5. Make sure all the optional safety switches are satisfied (airflow proving switch, high-limit
humidistat, etc.).
______ 6. After the humidifier is full of water, menu 004 will read “FULL” and the “Normal Operation” LED
will illuminate.
______ 7. Verify the low water safety circuit by closing the water supply and opening the manual drain lever
on the drain valve. As the humidifier tank is draining, the "Fill" LED should illuminate. The
humidifier should drain to a level where menu 004 reads “LOW”; this indicates that the low water
safety circuit is operational. Verify that the “Pilot Relay” is de-energized.
______ 8. Close the drain valve and allow the humidifier to fill to the proper level.
______ 9. Turn menu 101 “RH Setpoint” up to a call for humidity. If a Building Automation System is
controlling the humidifier have it call for 100% demand. For Building Automation System verify
0% and 100% demands are displayed as 0% and 100% on the INTAC®display or adjust the input
high and low values to match accordingly.
______ 10. The heater(s) should energize on a call from the humidistat.
______ 11. Check operation of optional field-installed safety switches (airflow proving switch, high-limit
humidistat, etc.) to make sure that they turn the power off to the control circuit power. The safety
switches should shut-off the humidifier heaters whenever one or more of the optional safety
switches create an “open circuit”.
______ 12. Check heater amperage draw by testing and recording voltage and amperage in each phase.
Readings should match the factory heater nameplate.
Amps A:_______ Amps B:______ Amps C:______
______ 13. Inspect installation for leaks by operating humidifier at a full rolling boil. This may take up to 15
minutes from a cold start. Any leaks should be sealed. Just tightening a pressure clamp will not
work if the gasket is not properly positioned between the sealing surfaces. If necessary remove
the cover, reseat gasket and replace the cover. A small amount of adhesive (super glue, gorilla
glue, spray adhesive, etc.) to hold the gasket in place while repositioning the cover will aid in this
process.
______ 14. After the unit is producing steam, check and retighten all hose clamp connections in the system
and make sure they are torqued to 35-40 in-lbs. There are 6 clamps total inside the cabinet.
Signature:__________________________ Date:_________

16
PURE Humidifier Co. “EC” Maintenance Instructions
The “EC” Series Electric Humidifier is designed to provide the best possible operation with minimum
maintenance. However, the humidifier should be inspected and place on a dedicated maintenance
schedule to ensure continued operation of the humidifier and its accessories. PURE Humidifier Co.
recommends that the following items be inspected, and/or, cleaned on a minimum basis of twice
a year. If excessive mineral buildup occurs, the maintenance schedule should be increased.
Maintenance & Cleaning Instructions
Inspect/Maintenance Item
Water Fill Valve
Safety Interlocks
(airflow, high-limit)
Immersion Heaters
Humidifier Cover/Tank
Tri-Probe Sensor
Drain Valve & Drain Piping
Flexible Hose
Procedure to Follow
Check to make sure the fill valve is operating properly. If the
valve appears to continually fill, check the valve seat and
seal (see Troubleshooting instructions).
Check to make sure the safety interlocks (airflow, high-limit,
etc.) will shut down the humidifier.
Verify the correct amperage is being drawn by the
heating element. Reference the wiring diagram for
correct amperage.
Inspect for any leaks. Repair as required. Remove the
mineral deposits from floor of the humidifier reservoir. If
excessive buildup is found, the cover may need to be
removed to facilitate complete cleaning of the humidifier.
Remove Tri-Probe Sensor from humidifier (set-screw and o-
ring seal) and inspect for excessive mineral buildup.
Inspect plastic housing for cracks. Probe ends should be
cleaned and the probe assembly re-installed.
The drain valve seat and seal should be inspected and
cleaned as required. The drain line and water seal should
be inspected and cleaned to ensure free flow of the overflow
and drain line.
Inspect for cracks or leaks. It is normal for the hose to
become hard and develop a “set”.
Cleaning Instructions
All humidifier tanks should be cleaned manually from the reservoir cover. Turn off the water supply,
disconnect controls by unplugging the molex in the small octagon box, disconnect power wire from
contactor and remove conduit connection from cabinet, disconnect all the hose connections from the
tank and slide the tank out of the cabinet. Remove all loose solids with a wet vacuum, stainless steel
brush, scouring pad, putty knife and/or bucket. Heaters should also be cleaned and loose build-up
removed by hand (if applicable). After removal of solids and replacing the cover you may wish to add
a de-scaling solution. DO NOT use Hydrochloric acid-based de-scalers; this will corrode stainless
steel. PURE Humidifier Co. recommends the use of a vinegar, citric acid, diluted phosphoric acid or
diluted nitric acid-based cleaner. Follow all precautions on the cleaner packaging. Some cleaners will
give off overwhelming and noxious odors, so make sure there is proper ventilation in the working area
and the steam outlet pipe is removed so that fumes are not spread throughout the building. After
cleaning the tank, flush the tank multiple times to remove any remaining acid. Drain tank completely
and allow the tank to air dry for a few hours. This will ensure that the outer protective layer of the
stainless steel will passivate and ensure corrosion resistance.

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Cover Gasket Replacement Instructions
Remove the reservoir cover. While looking at the top of the unit, reference Figure A and B to determine
which humidifier tank style you have.
Figure A Installation
Fit the gasket around the entire lip of the tank opening. Cut the gasket 1/8” longer than required, this will
ensure proper fit when the cover is clamped back on. Slide the gasket onto lip of tank around the entire
perimeter, and seal the ends together with a small amount of silicone.
Figure B Installation
Fit the gasket around the entire lip of the tank opening. Cut the gasket 1/8” longer than required, this will
ensure proper fit when the cover is clamped back on. Slide the gasket onto lip of tank around the entire
perimeter. Notch only the bottom flap of the gasket (reference Fig. C) in the corners of the tank. Seal the
ends together with a small amount of silicone.
Fig. A
Plan View of Humidifier
Fig. B
Plan View of Humidifier
Section View of Gasket
Gasket Bottom
Notch here
Bottom View of Gasket
Notch gasket bottom only
Gasket Top
DO NOT NOTCH
Fig. C

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Troubleshooting
Problem
Humidifier will not heat
Humidifier will not fill
Humidifier will not stop
filling or is short cycling
Possible Cause
Blown heater fuse(s)
Control transformer not
producing 24 vac control
voltage
Safety controls open
(air flow switch, high-limit, etc.)
Over-temp switch
Faulty humidity sensor
Faulty immersion heater
No water pressure
Drain valve open
No power to the fill valve
Fill valve stuck open
Drain valve open
Probes need cleaning
Check probe wiring
Line noise or radio frequency
Recommended Action
Check and replace.
Check transformer output, and verify voltage.
Verify that all safety controls are completing the
safety circuit.
The level control circuit has interference or is
damaged. Tri-probe Sensor wires should be run
separate from power wiring. Do not reset the
switch until the source of the problem is identified
and corrected. Consult factory if you are unsure of
the source of the problem.
Verify voltage to and from humidity sensor.
Check and verify heater voltage and
amperage. Compare to diagram or
nameplate label ratings.
Check water supply.
If auto drain system is utilized, verify that the
manual drain lever on the front of the drain valve is
closed.
Check for 24 vac across solenoid valve.
Check for 24 vac across solenoid valve. If no
voltage, check for dirt under valve seat.
Close drain ball valve.
If auto drain system is utilized, verify that the
manual drain lever on the front of the drain valve is
closed.
Remove Tri-Probe Sensor and clean probe ends.
Grey wire to probe #1 (shortest probe)
Violet wire to probe #2 (middle probe)
Blue wire to probe #3 (longest probe)
Shielded cable may be necessary.

19
Recommended Maintenance Tool List
7/16” Wrench
5/16” Nut Driver or Socket
11/32” Nut Driver or Socket
3/8” Nut Driver or Socket
5/32” Nut Driver or Socket
Flat head screwdriver
Wire stripper
Wire crimper
Tool Requirements & Torgue List
Torque List
Cover Bolts 18 inch/pounds MAX
Hose Cuff Screws 35-40 inch/pounds MAX when hot
Heater Nut 18-20 foot/pounds*
Heater Electrical Terminal 35 inch/pounds
* Use a pliers to hold heater sheath from twisting.
Cover
Heater Fiber Gasket
Heater Nut
Electrical Terminal Nuts
Metal Washer
Heating Element Sheath
Isolator
Heater Assembly Sectional Detail